Broadly tunable and robust UV laser generation on a chip

We present a detailed characterization of a hybrid photonic platform for robust and broadly tunable ultraviolet (UV) laser generation using Čerenkov nonlinear frequency conversion (CNFC). By integrating silicon nitride waveguides with barium borate (BBO) cladding, the platform achieves UV emission across an unprecedented wavelength range of 222–319 nm. Compared to state-of-the-art UV photonic devices, our approach addresses longstanding challenges in spectral range, tunability, and integration. Theoretical modeling and experimental validation demonstrate remarkable fabrication tolerance, maintaining phase matching over a 1500 nm waveguide width variation. These findings offer a compact, scalable solution addressing critical needs in disinfection, quantum technologies, and free-space optical communication.